Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Computing devices such as personal computers, laptop computers, tablet computers, cellular phones, and countless types of Internet-capable devices are increasingly prevalent in numerous aspects of modern life. Over time, the manner in which these devices are providing information to users is becoming more intelligent, more efficient, more intuitive, and/or less obtrusive. The trend toward miniaturization of computing hardware, peripherals, as well as of sensors, detectors, and image and audio processors, among other technologies, has helped open up a field sometimes referred to as “wearable computing.” In the area of image and visual processing and production, in particular, it has become possible to consider wearable displays that place a graphic display close enough to a wearer's (or user's) eye(s) such that the displayed image appears as a normal-sized image, such as might be displayed on a traditional image display device. The relevant technology may be referred to as “near-eye displays.”
Wearable computing devices with near-eye displays may also be referred to as “head-mountable displays”, “head-mounted displays,” “head-mounted devices,” or “head-mountable devices.” A head-mountable device (“HMD”) places a graphic display or displays close to one or both eyes of a wearer. To generate the images on a display, a computer processing system may be used. Such displays may occupy a wearer's entire field of view, or only occupy part of wearer's field of view. Further, head-mounted displays may vary in size, taking a smaller form such as a glasses-style display or a larger form such as a helmet, for example.
Emerging and anticipated uses of wearable displays include applications in which users interact in real time with an augmented or virtual reality. Such applications can be mission-critical or safety-critical, such as in a public safety or aviation setting. The applications can also be recreational, such as interactive gaming. Many other applications are also possible. Other personal image displays can be what is referred to as a heads-up display, wherein the image is displayed on, in, or through a transparent display that superimpose the displayed image over a view of the surrounding environment. These allow the user to view the image presented by the display simultaneously with their surroundings. Such devices, however, can have many limitations, including in their fit and comfort to their wearers as well as limited functionality.
Both head-mounted and heads-up displays can be connected to a video source that receives a video signal that the device can read and convert into the image that they present to the user. The video source can be received from a portable device such as a video player, a portable media player or computers. Some such display devices are also configured to receive sound signals, which are delivered to the user typically through incorporated headphones. The functionality of these types of displays is, however, limited to passive actions wherein the display simply receives information from an external source and presents it to the wearer in limited forms.
The positioning of the display in an HMD may vary depending on the individual wearer's preferences, the type of content being displayed, the conditions of use, or combinations of these and other factors. For example, some may prefer to have content that is intended to be viewed over a short period of time presented on a display that is positioned to not interfere with other activities. In another example, a display that is positioned to be out of the way can be uncomfortable for the user to focus on for longer periods of time needed to view other types of content. Such discomfort may be due to eye strain or positioning of the eye that results in a break between the lens of the eye and the eyelid.